Tool for metal seaming



S. SCOTT TOOL FOR METAL SEAMING I Sept. 8; 1942'.

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Sept. 8, 1942.

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Filed Dec. 18, 1940 s. sco'r'r TOOL FOR-METAL S'EAMING 3 Sheets-Sheet 2 "all! UM e M TOOL FOR METAL SEAMING Filed Dec. 18, 1940 3 Sheets-Sheet 3 s. scoT'r 2,295,131

Patented Sept. 8, 1942 UNiTED TES ,1 OFFICE.

FAT

8 Claims.

The present invention relates to improvements in tool for seaming metal, and has for an object to facilitate the joining of edges of sheets of metal or the like in an infolded seam joint.

More specifically, the improved tool has been developed with reference to the forming of seam joints between the walls of the ducts used in air conditioning or like systems, although it will be understood that the invention is not limited to this particular application.

Another object of the invention is to subject the forming tool to a composite motion consisting of longitudinal motion relatively to the work, by which action the shaping groove of the forming tool acts upon the edges of the seam to close such edges, and at the same time a reciprocating or vibratory motion imposed upon the formering member in a line at substantially right angles to the work or to the line of seam and in a general direction which will create hammer blows upon the ends of the seam in a direction in which the metal is being folded or moved into the closed seam.

A further object of the invention is to provide an improved method the steps of which are to simultaneously impose upon the ends of the metal to be seamed the before mentioned two component motions of longitudinal forming and lateral vibrations or hammering to the end that the movement of the tool relatively longitudinally to the work will be facilitated by the vibrating action of the tool, and such vibrating action will have the double function of also assisting the forming groove to beat down the edges of the metal into the seam.

A still further object of the invention is toprovide means for preliminarily forming the edges of two metal sheets to be seamed in such a way that they are preformed to lie in a diagonal plane with reference to the planes of the sheets, and in so arranging the forming tool with reference to this diagonal plane that it vibrates in such diagonal plane, thus assisting the forming groove of the tool in its passage with reference to the work and in its forming action upon the metal edges; it being understood that the preformed diagonal position of the edges of the sheets leaves only a relatively short angular distance to fold or bend those edges into the final seamed position whereby the vibratory hammering action of the diagonally disposed form,- ing member will, throughout such angular range, be highly effective in its hammering action upon the ends of the sheet metal up to the final complete closed position of the seam.

A still further object of the invention is to so organize and arrange the various parts into a mechanical tool that the preliminary dies may also be vibrated along with the vibration ofthe forming member and that such operation may be carried out efliciently and economically in an easily handled tool.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure l is a top plan view of an improved tool constructed in accordance with the present invention.

Figure 2 is a vertical section taken on the line 2-2 in Figure 1.

Figure 3 is a cross section taken on the line 3-3 in Figure 2.

Figure 4 is a longitudinal section taken on the line 44 in Figure 2.

Figure 5 is a similar view taken on the line 5--5 in Figure 2.

Figure 6 is a fragmentary enlarged side view of the preliminary dies.

Figure 7 shows a preliminary section of one metal sheet preformed with its seaming edge.

Figure 8 is a similar view of the companion metal sheet with its preformed edge.

Figure 9 is a perspective view from one side of the preliminary dies.

Figure 10 is a similar view taken from the opposite side.

Figure 11 is a fragmentary perspective view of the anvil and its cooperating forming member.

Figure 12 is a fragmentary inside face view of the forming member partly cut away.

Figure 13 is a diagrammatic view showing the initial condition of the preformed sheets in relation to the anvil and forming member.

Figure 14 is a similar view showing an intermediate condition of the seam during the forming action, and

Figure 15 is a similar View showing the final seamed condition of the parts.

Referring more particularly to the drawings, i6 designates the casing of an electric motor having a, frame connected thereto. This frame may be of any suitable form and character and connected to the motor in any desired way.

In Figures 1 and 5 the frame is shown to be composed of parallel side plates I1 and I8 extending out from the electric motor casing l6 and having curved members l9 and 20 for embracing the motor casing l 6 and being secured to one another as indicated at 2!. The side plates l1 and I8 are secured together as by bolts or other fastenings 22.

The motor shaft is represented at 23 and it carries a pinion 24 for meshing with a gear wheel 25 on an operating shaft 26. This operating shaft is mounted in bearings 2! and 28 in a gear casing 29 carried by the frame members. Such operating shaft 26 is formed or otherwise provided with an eccentric 39 over which is engaged an eccentric strap or link 3! pivoted at 32 to a link 33. Such link 33 is in turn pivoted at 34 to an arm 35 of a rocker 36. The rocker is carried upon a shaft 31 journaled in the frame. The rocker 35 carries a movable die member 38 for cooperating with the fixed dies 39 and 40 supported in the frame. Such rocker 36 has an upstanding preferably diagonally disposed arm 4! pivoted at 42 to the forming member 43.

The forming member 43 cooperates with an anvil 44 carried by a guide 45 and such guide is fixedly carried by the side plates I! and I 8 of the frame by being included between said side plates and bolted or otherwise secured thereto. The guide 45 and its anvil 44 form a substantial goose neck between which parts the outer end or pilot 46 of the forming member 43 slidingly fits. Such outer end of the forming member is reduced to the end that the pilot 46 may slide along the outer member of the seam while the anvil 44 engages the closed side of the seam. As shown more particularly in Figures 13, 14 and 15 the anvil 44 is so shaped as to lie in part against the upper face of the sheet 41, upwardly along the flange 48 of the sheet and in part above the curved upper edge of the flange 48 at a point where the flange extends over into the web 43 which constitutes one edge of the metal seam to be formed.

As seen in Figure 13 the free edge of this web 49 is given a preformed curve 56 in the direction in which the metal is to be folded into the seam. The sheet metal member 4! in its preformed state is shown individually in Figure 8.

The companion member is shown individually in Figure 7 in its preformed state as having a web 52. The web 52 is formed in the preliminary die 38, 39. The web construction 49 shown in Figure 8 is preformed in the preliminary die 38, 40. After such preliminary forming as shown individually in Figures 7 and 8 the two members 41 and 5| are assembled into the initial assembled condition illustrated in .Figure 13.

The anvil 44 and the forming tool 43 are thereupon applied to such assembled sheet metal walls and either the tool as a whole is run along the longitudinal line of the seam, as indicated in Figure 1 or the work, meaning the conduit walls 41 and 5! in their assembled state, are drawn through the tool. However it will be preferred in most instances to move the tool along the stationary work and for this purpose a handle 53 is mounted upon the frame and projects radially out from the motor casing it. The arrow in Figure 1 indicates the direction of motion of the tool, the handle 53 being grasped and pushed parallel to the line of the seam.

The die 39 which, in association with the lower part of die 38, gives to the sheet 5! its preformed shape is illustrated more particularly in Figures 6, 9 and where the die member 39 is formed with a wall gauge 54 to limit the movement of the metal 5| as it is inserted in the die or as the die is applied over the edge of the metal as indicated in Figure 6.

The forming wall is indicated at 55 and it is of spiral formation for the purpose of overturning the edge of the sheet metal. Such forming wall ends in an overhanging part 56 adapted to overlap with a V-shaped member 5'! on the movable die 58. The wall 55 and its overhanging part 56 simply overturn the edge 52 upon the V-shaped member 51. The top preliminary die 40 serves to form the other joint edge of the sheet metal wall 4! and it consists of a rib 58 upstanding from the member 38 and corresponding with a groove 59 of the upper fixed die 40. As seen in Figure 10 the rib and the groove are generated at the leading edges of the die members and taper progressively up to full proportion in the trailing edges of the die members so that as the tool is moved along the edges the flange or shoulder 48 is formed along this rib 58 and its groove 59. It will be noted particularly from Figure 9 that the inner face 63 of the rib 58 is sloping and this sloping characteristic imparts form to the diagonal web 49 shown in Figure 8. The sloping wall 63 also cooperates with the sloping wall 6| of the die member 40 and these walls are angularly turned from the leading to the trailing edges of the dies in order to fashion the web 49 gradually and progressively as the tool is moved relatively to the sheet 41. At the lower end of the sloping wall 60 a substantially vertical wall 62 which cooperates with vertical wall 63 of fixed die 40. These walls 62 and 63 impart form to the free edge 50 as shown in Figure 8.

The forming member 43 and its anvil 44 are shown more particularly in Figures 11 and 12. The anvil has been heretofore described. The forming member 43 is formed with a groove which is a composite of two grooves, namely the semi-circular curve 64, as shown in Figure 11, and the tapering bottom wall of the groove, as shown in Figure 12. The arrow in Figure 12 indicates the direction of movement of the forming member 43 with reference to the longitudinal line of the seam so that the lower part of the tapering bottom wall 65 encounters the work first. As the tool is slid along with reference to the work the taper of the bottom wall 65 causes such bottom wall to approach closer to the anvil and thereby tends to close the seam. The semi-circular wall 64 acts upon the preformed edge 50 to cause the same to curl around such semi-circular wall 64, as indicated by the comparative views in Figures 13, 14 and 15.

In operation, either the tool or the work is moved. For convenience in description the tool is described as the movable member but it will be understood that if the tool remains stationary the work may be drawn therethrough and accomplish the same results.

The sheet 5| shown in Figure '7 is first formed by inserting the same in the lower preliminary die in the manner indicated in Figure 6. Either before or afterwards the companion sheet 41 shown in Figure 8 is formed by inserting the same in the upper preliminary die as indicated in Figure 6. The members of these dies are so constructed as to give the forms represented in Figures '7 and 8 on relative longitudinal movement between tool and sheet. In this action the die performance is materially assisted by the Vibration of the die member 38 which partakes of the oscillating motion of the rocker 36. This motion will preferably be through only a very slight angular distance and the gear ratio from the motor will be such that the oscillations are Very rapid. Such oscillations are at right angles to the plane of the sheet passing through the die and therefore the sheet will be hammered by the vibrations into the matrices of the die members.

When the two sheets shown in Figures 7 and 8 are formed they are set up as shown in Figure 13 with the sheet for instance vertical and the companion sheet 4! horizontal, the flange 48 enabling the sheet 61 to fit down within or below the upper edge of the sheet 5! and to form an interlock with the upper edge portion of the sheet 5i.

The webs 43 and 52 will thus extend one above the other and in a diagonal position extending downwardly from the upper edge of sheet 5| and the upper edge of flange 48. In this condition the tool is applied as indicated in Figure 3. Figures 13, 14 and 15 are exaggerated in illustration with respect to the reciprocating or vibrating motion of the forming member 43.

In reality this movement is a very small rectilinear movement amounting substantially to vibration but having a definite line of thrust against the webs and laterally of the longitudinal line of the seam. In other words this Vibration takes place at substantially right angles to the longitudinal length of the seam and therefore generally in line with the folding movement of the webs. This vibration causes the walls of the forming groove of the member 43, during the longitudinal movement which constitutes the forming and shaping action, to vibrate constantly against the webs being formed which contributes to the ease of the passage of the tool with reference to the work and at the same time directly hammers the webs into the finished seam. It will be understood that the forming groove of the member 43 is not materially changed or enlarged on account of the vibrating movement given to the chamber 43 but that the vibrations are extremely small in length of movement.

The angle of thrust of the finishing die 423 in relation to the plane of the two sheets 4'! and 5| of the metal to be seamed is important because where the webs 59 and 52 are preformed in the diagonal as against for instance the horizontal, the finishing die has only to turn the webs approximately 45 instead of through 90 which would be necessary with webs that were preformed in the horizontal. There is therefore a mechanical advantage in preforming the dies in the diagonal but this mechanical advantage is especially important where vibration is imparted to the forming member 43.

Naturally there is an ideal line of thrust which will be most efficient and as the angle of the seam changes such seam is apt to move out of that line. Provided the angular movement of the seam is within limits and does not depart too far away from such line of thrust the implement will remain efiicient. The line of thrust at the beginning of the action upon diagonal webs such as shown in Figure 3 will be a diagonal position of the line of vibratory thrust of the member 43 and the angle of 45 through which the webs move in closing the seam will not exceed the emciency of the tool 53; particularly inasmuch as the curvatures G4 and 65 closely follow the Webs in their angular closing movement so as to transfer the eifective thrust around to follow the closing movement of the seam.

It will be clear therefore that to have too wide an angle for seam closing, such as the 90 required if the webs were horizontally preformed,

is to possibly lose the efiiciency of the vibratory action particularly at the end. of angular movement of the webs where it is most desired to hammer the seam into tightly closed condition. The shoe or anvil 44 opposed the thrust of the reciprocating tool 43. The diagonal angle of thrust also enables me to reduce the width of the edges of the metal to be seamed. Such unduly wide edges produce a large and unsightly seam. With the diagonal line of thrust the method is more reliable and makes a heater job with narrower webs. The shoe or anvil 44 engaging the closed side of the seam forms a guide for guiding the machine along the work.

t will be appreciated that the three dies. are identical in principle and that all three mutually cooperate to a single unitary result.

The oscillating movement or reciprocating movement of the dies has been found to be satisfactory on a stroke of approximately one-eighth inch at 2,600 B. P. M.

The diagonal arrangement of the die 53 in connection with the shortened edges of metal to be seamed will be more apparent by considering a horizontally reciprocating die in connection with the sheet metal wall 5i having a horizontally projecting flange with an inclined forming wall on the horizontally reciprocating die. If the sheets of metal are of light gauge and the flange fairly wide no great downward pressure on the tool is needed to perform the desired bending operation. If the thickness of the metal sheets is increased and the width of the flange decreased, it is apparent that the upward thrust on the die is very great, and that a proportionate weight must be added to counteract this upward thrust. This increased weight, either added to the machine or by downward pressure of the operator, is undesirable and seriously affects the efficiencyof the machine as a whole.

Insufiicient downward thrust will result in the die no longer tending to form a fine wall seam, but rather to force itself higher and higher. The diagonal arrangement of the die obviates this tendency of the machine to rise and forms a neater and more compact seam with less efiort by the operator.

An added feature of the new arrangement is that the work done by the three dies is more evenly divided, permitting the use of a maller motor and lighter construction.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described em bodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:

1. A portable metal seaming tool comprising a frame, an electric motor connected to said frame, a handle for moving said frame and electric motor longitudinally along the line of the seam, guide means for engaging the work at one side of the seam, means for supporting said guide means from said frame, a forming member movably mounted on said frame and directed by said frame to move laterally of the line of the seam and in line with said guide means, connections between said electric motor and said forming member for vibrating said forming member laterally of the seam, said forming member having a forming groove extending longitudinally of the line of the seam and operable to form a seam by movement longitudinally of the seam and laterally of the seam.

2. A metal seaming tool comprising a frame, a :motor connected to said frame having a motor shaft, an operating shaft carried by said frame, means housed in said frame for transmitting motion from the motor shaft to the operating shaft, an eccentric on said operating shaft, an eccentric strap about said eccentric, a forming member mounted to vibrate in said frame and coupled to said eccentric strap, said forming member having a forming groove extending longitudinally of the line of the joint and operable to form a seam by movement longitudinally of the seam and laterally of the seam.

3. A metal seaming tool comprising a frame, :a vibrating forming member movably carried by .said frame and directed to vibrate at substantially right angles to the line of th seam, an eccentric carried by said frame, an eccentric strap in driven relation to said eccentric, means connected to the frame for driving said eccentric, said forming member having a forming groove extending longitudinally of the line of the seam, means for driving said forming member from said eccentric strap, and guide means carried by said frame and positioned thereon with reference to said forming member that said guide means engages the closed side of the seam While the forming member is engaging the open side of the seam to close the same.

4. A metal seaming tool comprising a frame, a reciprocating and laterally movable forming member carried by said frame, means for reciprocating said forming member as it is moved longitudinally relatively to the work, a guide member carried by said frame in substantial alignment with the line of reciprocating thrust of said forming member to act as a backing or abutment for the reciprocating motion of said forming member, said forming member having a forming groove operable by movement longitudinally and laterally f the seam to form a closed seam.

5. A portable seaming tool comprising a frame, driving means connected to said frame, means for moving said frame and driving means longitudinally along the line of the seam, guide means on the frame for engaging the initially closed side of the seam, means for supporting said guide I means between said driving means and said forming member for reciprocating said forming member.

6. A seaming tool comprising a frame, a form ing tool having a forming groove therein lying as to length in substantial alignment with the longitudinal length of the seam, said groove composed of a composite curve, said composite curve having as components a substantially circular curved wall and a diagonal curved component, means on th frame for supporting said forming tool for vibratory motion with respect to the frame at right angles to the longitudinal line of the seam and in substantially the same direction as the direction of fold or bending of the edges of the seam, and means on the frame for said forming tool adapted to cause said tool to vibrate with relation to the frame during the relative movement of the work and the tool with respect to each other along the line of the joint, the whole operating for the purpose of simultaneously superimposing on the forming tool a composite motion comprising longitudinal forming and lateral hammering of the ends of the seam.

'7. A tool for seaming metal and the like comprising a forming member movable both longitudinally 0f the seam and at substantially right angles to the line of the seam, said forming member having a forming groove therein shaped to fold the ends of the metal together in a closed seam on the relative longitudinal movement of the work and forming member, and means coupled to and acting on said forming memlber throughout its longitudinal relative motion with respect to the seam forvibrating said forming member in a vibratory line of thrust at substantially right angles to the line of the seam and in the general direction of the line of bending of the ends of the seam members to both facilitate the relative longitudinal motion of the forming member and the work and at the same time by rapid hammering on the seam ends to greatly assist the forming groove in closing the seam ends.

8. A seaming tool comprising a frame, an anvil member carried by said frame for movement relatively along one side of a seam to be formed, a forming member having a forming groove also carried by said frame in a movable manner relatively to the frame and to said anvil and disposed opposite to and from said anvil, a rocker member mounted on said frame and coupled to said forming member, and means coupled to said frame and to said rocker member for causing rapid oscillation in said rocking member.

STANLEY SCOTT. 

